In general, fine patterns which are used in display devices such as semiconductor circuit devices and LCDs (Liquid Crystal Display) are formed according to a photolithography process by using a photoresist. In connection with this, the photoresist is applied on the substrate, exposed, developed, washed, and cured to produce the fine pattern. Even though the photolithography process is advantageous in that desired patterns are precisely obtained, there are disadvantages in that many steps are performed, various types of materials are used in order to maximize the effect of the photoresist, and a great amount of photoresist is used during processes such as a coating process. In recent, a method for obtaining a fine pattern by using an inkjet printing process has been suggested in order to avoid the disadvantages of the photolithography process.
With respect to the production of the color filter by using the inkjet printing process, a BM (black matrix) which is a light blocking part is formed by using a known photolithography process, and three types of ink having R, G, and B colors are jetted into pixel units between the light blocking parts used as partitions. A manufacturing method of a color filter by using the inkjet printing is shown in FIG. 1. In connection with this, if the light blocking part used as the partition does not have the ink repellency in respects to the ink, the ink which is jetted into the pixel units between the light blocking parts flows through the light blocking part from the pixel unit to the adjacent pixel unit, which may cause color mixing in respects to the same color or the different colors. Therefore, it is required that the light blocking part pattern which is used as the partition during the inkjet printing has the significantly high ink repellency in respects to the ink.
On the other hand, the jetted ink is uniformly spread in the pixel units only when the surface of the glass substrate of the pixel units between the light blocking parts has the low ink repellency in respects to the ink, which prevents light leakage due to unfilling of the pixel units and reduces steps in the pixel unit or between the pixel units. However, if the light blocking part pattern is made of a light blocking part material having the high ink repellency, due to the post-baking process, the surface of the glass substrate of each of the pixel units is reformed so that the surface of each of the pixel units has the ink repellency similar to that of the surface of the light blocking part. Accordingly, even though the ink is jetted, the ink is undesirably spread in each of the pixel units to cause the unfilling and significant steps in the pixel unit or between the pixel units. The light blocking part and the pixel unit that are formed by using the above light blocking part pattern are shown in FIG. 2, and unfilling of ink due to the material having the ink repellency adsorbed on the pixel unit is shown in FIG. 3.
In order to avoid the above-mentioned problems, Japanese Unexamined Patent Application Publication No. 1997-203803 discloses a method of performing surface treatment in respects to a main unit by using an ink affinity treatment agent and surface treatment in respects to a projection unit by using an ink repellency treatment agent. However, this method is problematic in that the treatment is performed by using the ink affinity treatment agent so that the ink repellency treatment agent is not affected or two treatment processes are separately performed by using the ink affinity treatment agent and the ink repellency treatment agent.
Furthermore, Korean Unexamined Patent Application Publication No. 2000-0047958 discloses a color filter which has a wettability-variable layer capable of changing the wettability. However, this method is disadvantageous in that the wettability-variable layer is separately provided in addition to a partition layer which is a light blocking part and an ink layer which is an opening part, thus complicating the production process.
Additionally, Japanese Unexamined Patent Application Publication No. 2000-258622 discloses a method of pattern exposing a photosensitive layer to convert an exposed portion into a hydrophilic portion. However, in this method, it is required that an additional process is performed to form an additional photosensitive layer.